very high conductivity region in semiconductor devices acting as a source of free majority carriers typically injected into the adjacent region (for instance into base in the bipolar transistor)

bipolar device

semiconductor device which operation is based on the use of both majority and minority charge carriers; all p-n junction based devices fall into this category; alternative to unipolar device.

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common emitter configuration

circuit configuration of a bipolar transistor where base is the input electrode, collector is the output electrode and emitter is the reference electrode for both input and output.

common base configuration

circuit configuration of a bipolar transistor where emitter is the input electrode, collector is the output electrode and base is the reference electrode for both input and output.

common base cut-off frequency

frequency at which the current gain in the common-base configuration of bipolar transistor drops to 1.

common emitter current gain

the ratio of the collector current to the base current.

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common emitter current gain

the ratio of the collector current to the base current.

common emitter configuration

circuit configuration of a bipolar transistor where base is the input electrode, collector is the output electrode and emitter is the reference electrode for both input and output.

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common emitter cut-off frequency

frequency at which the current gain in the common-emitter configuration in bipolar transistor drops to 1.

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emitter injection efficiency factor

factor defining efficiency of majority carrier injection from the emitter to the base (where they become minority carriers)of a bipolar transistor; should be as close to 1 as possible.

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emitter push effect

occurs in n-p-n junction bipolar transistors; part of the boron doped base region which is in contact with phosphorous doped emitter region is deeper than part of the base which is not in contact with emitter; this effect is due to the dissociation of phosphorus-vacancy pairs which enhance diffusion of boron deeper into the substrate under the emitter region.